While he said he likes the way the offense is progressing overall, Nelson definitely has concerns about the offensive line.

That's because several O-linemen have not been participating fully due to injuries or other reasons, causing the coaching staff to play a variety of personnel groups, and creating a lack of continuity.

Nelson expressed some frustration about that after Saturday's practice.

"It all starts up front. I haven't had the same five guys in front of me from one day to the next," Nelson said. "That's frustrating. But at the same time, there's nothing I can do to control that, so I can't worry about that. Neither can the coaches or the other players. It's up to each one of those guys to do what they've got to do to get back on the field. In some cases, that's rest and letting an injury heal. In other cases, there are things they can do that they can control and they need to do that. The sooner the better, as far as the offensive line is concerned."

Coach Bronco Mendenhall said none of those injuries are severe enough to prevent them from playing in the season-opener against Washington State on Aug. 30.

During spring ball, BYU's offensive line was decimated by injuries and offseason surgeries. There were so few O-linemen available that it limited what the offense was able to do.

During the offseason, the coaching staff had the linemen slim down so they could be more mobile.

"They are trimmer and they're more fit and there's more of them," Mendenhall said Saturday. "Not only more players, but more depth. So it's good."

But because they've had so little time together as a group, cohesion is a question mark.

"Of course it's a worry, but there's nothing we can do about it," Nelson said. "We'll just keep getting work with the guys that we have. In the meantime, hopefully those guys are doing everything they can to get on the field. We need them, that's for sure."

Since Thursday's scrimmage, the coaching staff has been in the process of solidifying the depth chart. But the absence of key offensive linemen is making it tough, according to Nelson.

"It's been a focus up to this point, we just can't seem to do it," Nelson said of the depth. "We've got to get over the hump. I don't know, though. That's why they pay the coaches the big bucks, is to make those decisions, to decide when a guy needs a rest, when a guy needs to come out, what requirements to set for those guys and what requirements they have to meet to play on the field."

Injuries: Tight end Marcus Mathews remained sidelined while dealing with an illness.

Overheard: "You have to conserve your energy where you can conserve it. Forgive me for not having as many quips as normal. Let's just say I'm grateful for the Sabbath." — Quarterback Riley Nelson, when asked why he seemed "a little despondent" during his conversations with the media on Saturday.